Loop-retainer for sewing-machines



I..R. MOFFATT AND R. S. KELSO. I LOOP RETAINER FOR SEWINGMACHINES.

APPLICATION FILED AUGJZ, I918.

Patented Aug. 24, 1920.

2 SIIEETS-SHEET 1.

I. n. MOFFATT AND a. s. KELSO.

LOOP RETAINER FOR SEWING MACHINES.

APPLICATION FILED AUG.22| 19 18.-

I,350 931, Patented Aug. 24, 1920.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

JAMES R. MOFFATT AND RALPH S. KELSO-,,OF CHICAGO, ILLINOIS, ASSIGNORS T UNION SPECIAL MACHINE COMPANY,'OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

LOOP-RETAINER FOR SEX/VIN G-MACI-IIN ES.

Application filed August 22, 1918.

To all whom it may concern.-

Be it known that we, JAMES R. MOFFATI and RALPH S. KELSO, citizens of the United States, residing at Chicago, in the county of Cook, State of Illinios, have invented certain new and useful Improvements in Loop- Retainers for SewingMachines, of which the following is a description, reference be ing had to the accompanying drawing and to the figures of reference marked thereon.

The invention relates to new and useful improvements in sewing machines and more particularly to a sewing machine havlng a threaded looper moving back and forth m a plane parallel with the feed. granted to Lansing Onderdonk, January 5, 1915, No. 1,123,576, a sewing machlne of the above type is illustrated and associated with each looper is a device for engaging the looper thread for holding said looper thread away from the body of the looper so as to permit the needle to pass with certainty between the looper thread and the body of the looper.

An object of the present invention 1s to provide a retainer of the above character for holding the looper thread away from the body of the looper, which retamer s supported by a shank extending in the d1- rection of the feed of the machine, so as to give suflicient space for a section of the feed dog at the side of the needle.

A further object of the invention is to provide a multiple needle machine with a detachable and independently supported retainer for each looper. I

A still further object of the inventlon 18 to provide a retainer having a supporting shank disposed parallel with the lineof feed and seated in a groove in the under face of the throat plate, which shank is detachably held in the groove.

These'and other objects will in part be obvious and will in part be hereinafter more fully disclosed.

In the drawings which show by way of illustration one embodiment of the inven tion; I I v Figure 1 is a bottom plan view of the throat plate of a sewing machine having our improved retainer attached thereto;

Fig. 2 is a top plan view of the throat plate;

Fig. 3 is a sectional view on the line 33 of Fig. 1;

Specification of Letters Patent.

In the patent Patented Aug. 24, 1920. Serial No. 250,946.

Fig. l is an inverted sectional view on the line k-4 0 ig. 1;

Fig. 5 is a bottom perspective view of a portion of the throat plate and one of the retainers, the parts being separated;

Fig. 6 is a view showing in vertical sec tion and more or less diagrammatically a part of a sewing machine having our im proved retainer applied thereto;

Fig. 7 is a perspective view from the under side of the throat plate showing the looper, a portion of the throat plate and the retainer with the looper at the forward end of its stroke and moved laterally in order to avoid the needle; and Fig. 8 is a View similar to Fig. 7 but showing the needle and also showing the looper as partly retracted, the needle being well into the thread triangle formed by the body of the looper, the looper thread and the needle thread loop extending to the previous needle puncture.

In the patent to Onderdonk referred to above, the looper is a threaded looper and moves forwardly in the plane of the feed and opposite to the direction of the feed as it enters the needle thread loop. The looper is then given a lateral or needle avoiding movement. i As the looper moves laterally and then begins its backward travel, the looper thread which extends rearwardly from the eye of the looperthrough the needle thread loop around the looper, is retained against a stationary separates the looper thread from the body of the looper so that the needle will with certainty enter between the looper thread and the body of the looper. The needle must enter the looper thread loop in order to properly concatenate the thread loops and form stitches. Inasmuch as the looper lies in a vertical plane containing the feed, the movement of the fabric during the feed stroke, carries the previously formed aperture in the fabric formed by the needle into which the thread leads, rearwardly over the looper so that the feeding movement of the fabric does not have any effectin the forming of the usual triangle for the needle to enter, as occurs when the looper moves transversely of the line of feed. Some means, other than the feeding mechanism and the movements of the looper, is necessary, therefore, when the looper moves in the line of feed to separate the looper thread projection which i needle 3, beneath Y support by a feed plished in the Onderdonk patent by the retaining finger, which is engaged by the looper thread, so that the looper thread will be held out away from the looper and thus permit the needle with certainty to pass between the looper thread and the body of the looper. In the Onderdonk patent these retaining devices are all carried by a bar extending transversely of the line of feed.

If one is adjusted, all must be adjusted. If

one is replaced, all must be replaced, and, furthermore, the bar'extends across the line of feed and, therefore, no feed section of the feed dog can be placed along side ofor between the needles, and to extend from a point in front of to a point in rear of said needles. The present invention is directed to improved means of supporting andarranging the retainer for accomplishing'the purposes set forth in this patent. In carrying out our present invention, we have provided a separate and independent means of supporting each retainer. formed as a part of a shank, which shank is located in the line of feed and each shank is separately secured by a screw in an independent groove inthe underface of the throat plate.

Referringmore in detail to the drawings, we have shown ourinvention as applied to a sewing machine having a worlr-support 1 which is provided with a throat plate 2. The stitching mechanism includes a plurality. of needles, one of which is indicated in Fig. (i at 3. The throat plate as illustrated in Figs. land 2,v is provided withfour needle slots indicated at f, and there is, of course, a needle for each slot. Cooperating with each the work support is a looper 5. This looper is a threaded looper. The looper 5 ismounted on a looper carrier 6, carried by a shaft 7. r This shaft '7 is oscillatedand moved endwise in any suitable way, the patent to Cnlerdonk referred to above, showing one way in which the proper movements may be imparted to the looper. The material is held on the work support by a pr'esser foot 8 and is fed across the work dog 9. These parts are The throat is all of the usual construction. plate, as clearly shown in Figs. 1 and 2,

formed witha series of slots 10 for the sections of the feed dog.

It will be noted that these feed slots'not only extend directly in rear of the needle slots, but along side of the same and to points well in front of the needle slots) The feed sections are also constructed so as to operateupon the material in rear of the needle,;atthe side of the needle andto a point well in advance of the needle.

Associated with each looper is a retainer 1. This retainer is formed with a shank l2 and the throat plate is formed in its under Theretainer is above the plane in advance of the needle.

looper moves face with grooves 13 for the shanks of the respective. l'et211I1GlS.,... These grooves are preferably milled'in the throat plate and of each groove is therefore The shank of the rear end curved,'as indicated at l t.

the retainer is tapered and swaged to one side, so as to form an inclined thread retaining surface 15. The throat plate at one side of the groove for *the shank is further grooved to form a clearance space for the looper thread, as indicated at 18 in the drawings. This clearance groove is located directly above the looper when said looper is on its forward travel, so as to readily receive the looper thread extending rearwardly from the eye of the looper. The tapered end of the shank having the inclined thread retain ing surface partially overlaps this thread groove, as clearly shown in the drawings. hen the retainer tive groove, the curved surface l i of the groove positively holds the end of the retainer, indicated at 16, so that it is slightly of the lowrr' surface of the throat plate and partially overhangs the thread clearance slot, as above noted. The retainer shank is held in its respec ve groove by a screw 17. This screw 1? has its head overlapping the shank of the retainer, so as to securely hold the same in place. liy loosening the screw, the retainer may be adjusted endwise in the groove.

It will not only be seen that the retainer for each looper is independently mounted and independently adjustable, but as the shank extends substantially in the direction of the feed, it does not in any way interfere with the operation of a section of the fetal dog at the side of the needle at a point well In operation, let us assume that the needle is all the way down and the looper at the rear end of its stroke. 't

As the needle rises l casts out the needle thread loop and simnlta neously with the rise of the needle, the forwardly into the needle thread loop. As the looper continues its forward movement, the looper thread extending rearwardly from the eye of the looper to the last formed thread concatenation is positioned within the clearance groove 18 and on the left hand side of the retainer. The looper then avoids to the right and at this time the needle is beginning its descent,

Also at this time the looper thread extending I rearwardly from the eye of the looper is in a slack condition andis against the retainer on account of the reduced or tapered end of said retainer projecting partially across the thread clearance groove. 5 s the looper starts on its retracting or backward movement, and before the needle even reaches the fabric, the looper thread is caused. to form loop and this loop extendin around th tainer is held by said retainer in its open relation until the needle point has descended into said loop. As soon as the needle point has descended well into the loop, the looper during its continued backward movement draws the loop from off the point of the re tainer. if it were not for the retainer, this strand of looper thread which extends rearwardly from the eye of the loopei might do any one of the follow; things(l) It might bow out quickly in the proper direction and remain in that condition until the needle has entered the loop; or (2) it might feed through the eye of the looper and thereby bow outwardly away from the looper but on the wrong de thereof, thereby preventing the needle from entering the loop; or (3) it might partake of a sinuous twist like a compound curve and thereby be positioned on the wrong: side of the needle.

It is obvious that minor changes in the details construction may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus fully described our invein tion, what we claim as new and desire tocure by Letters Patent, is:

1. The combination of a needle, a feeding mechanism, a threaded looper moving into and out of the needle loop in a line substantially parallel with the line of feed, said looper having a lateral needle avoiding movement while in the needle loop, a throat plate having a needle opening therein, said throat plate having a thread clearance groove formed in its underface leadingforwardly from the needle opening, anl a retainer d-t-ltachably secured to the under surface of the throat plate and having its rear end partially overlappin said groove for retaining the looper thread during the lateral movement of the looper and durin the first part of its backward movement so as to insure the needle passing between the looper thread and the body of the looper.

The combination of a feeding mechanism, a plurality of needles arranged in a line substantially at i'aht angles to the ine of ed, a thread carry my; looper coiipe i wnh each needle, each looper moving in a line substantially parallel with the line of feed while entering and withdrawing from the needle loop and having its loop taking mo *ement opposite to the direction of feed, each looper being moved transversely of the line of feed to avoid the needle while in the needle loop, a threat plate having an opening" for each needle and a thread clearance groove extending forwardly from each needle opening, and an independently mounted retainer for each looper, said retainer having a thread retaining shoulde 1y overlapping the thread clearanc for retaining' the looper thread and h,v the same away from the body ()"g the looper until the needle in. its descent has entered between the looper thread and the body of the loope-r.

3. The combination of a feeding mechanism, a thr at plate having a needle opening, a needle, a threaded looper movable in a line substantially parallel to the line of feed while entering and withdrawing from the needle loop and movable transversely to avoid the needle while in the needle loop, said throat plate having a groove formed in its underface directly in front of the needle opening and parallel with the line of feed, a retainer having a shank mounted in said groove, said retainer operating to engage the looper thread for holding the same away from the body of the looper until the needle in its descent has entered between the looper thread and the body of the looper, and means for holding the retainer in the groove.

t. The combination of a feeding mech anism, a throat plate having a needle opening, a needle, a threaded looper movable in a'line substantially parallel to the line of feed while entering and withdrawing from the needle loop and movable transversely to avoid the needle while in the needle loop, said throat plate having a groove formed in its underface directly in front of the needle opening and parallel with the line of feed, a retainer having a shank mounted in said groove, said retainer operating to engage the looper thread for holding the same away from the body of the looper until the needle in its descent has entered between the looper thread and the body of the looper, and means holding the retainer in the groove, said throat plate havin a feed slot formed therein extending from a point in rear of the needle opening and alongside of the shank to a point in advance of the needle opening.

5. The combination of a feeding mechanism, a throat plate having a plurality of needle openings, needle for each opening, threaded looper cooperating with each needle movable in a line parallel with the line of feed and movable transversely to avoid the needle while inthe needle loop, said throat plate having a groove formed therein directly in front of each needle opening, an independent retainer for enthe looper thread of each looper for holding the looper thread away from the body of the looper until the needle in its descent has entered bet-ween'the looper thread and the body of the looper, said retainer for a shank seated in its in the throat plate, means each looper having respective groove for holding the shank in said groove, said retainer being shaped adjacent the needle opening; to form m inclined thread retaining; shoulder.

6. The combination of a feeding mecha .ism, a throat plate having a plurality of needle openings, a needle for each opening,

' holding the looper a threaded loopercoiiperating witheach needle movable in a line parallel with the line of feed and movable transversely to avoid the needle while in the needle loop, said throat plate having a groove formed therein directly in front of each needle opening, an independent retainer for engaging'the looper thread of each looper for holding the looper thread away from the body of the looper until the needle in its descent has entered between the looper thread and the body of the looper, said retainer for each looper having a shank seated in its respective groove in the throat plate, means for holding the shank in said groove, said retainer shank being shaped adjacent the needle opening to form an inclined thread retaining shoulder, said throat plate having 'a clearance groove formed therein adjacent each inclined shoulder on the shank and above its respective looper when saidlooper is on its forward travel, so as to receive the looper thread extending .rearwardly from the eye of itsassociatcd looper.

7. The combination of a feeding mechanism, a throat plate having a plurality of needle" openings, a needle for each opening, a threaded looper cooperating with each needle movable in a line parallel with the line of feed and movable transversely to avoid the needle while in the needle loop, said throat plate having a groove formed therein directly in opening, an independent retainer for engaging the looper thread of each looper for thread from the body of the looper until the needle in its descent has entered between the body of the looper, said retainer for each looper having a shank seated in its respective groove in the throat plate, means for holding the shank in said groove, said retainer shank being shaped adjacent the needle opening to form an inclined thread retaining shoulder, said throat plate having a clearance groove formed therein adjacent each inclined shoulder on the shank and above its respective looper when said looper is on its forward travel, so as to receive the looper thread extending rearwardly from front of each needlethe looper thread and the eye of its associated looper, said throat plate having a feed slot in rear of each needle opening and at one side of each needle opening.

8. The combination of a feeding mechanism, a plurality of needles arranged in a line substantially at right angles to the line of feed, a thread carrying looper cooperating with each needle, each looper moving in a line substantially parallel with the line of feed while entering and withdrawing from the needle loop, each looper being moved transversely of the line of feed to avoid the needle while in the needle loop, a throat plate having an opening for each needle, an independently mounted retainer for each looper for holding the looper thread away from the body of the looper, the retainer for each looper having a shank extending parallel with the line of feed, said throat plate having a feed slot formed therein in rear of each needle opening and extending along side of the needle opening to a point in advance thereof.

9. A throat plate having a plurality of needle openings, each of which is adapted to receive a needle, said throat plate having a groove formed therein directly in front of each needle opening, an independent retainer associated with each needle opening and adapted to hold the looper thread away from the body of the looper, each retainer having a shank seated in its respective groove in the throat plate, means for bold ingthe shank in said groove, each retainer being shaped adjacent the needle opening to form an inclined thread retaining shoulder, said throat plate having a clearance groove formed therein adjacent each inclined shoulder and disposed so as to receive the looper thread extending rearwardly from the eye of its associated looper.

In testimony whereof we affix our signatures in the presence of two witnesses.

JAMES R. MOFFATT. RALPH S. KELSO.

Witnesses:

S. GEORGE TATE, O'r'ro Gr. DOHSE. 

